[JS/TS] Fix TypeScript compilation by resolving type of jsOptions

src/Fable.Cli/CHANGELOG.md

@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * [JS/TS] Fix escaping of `{` and `}` in FormattableString (#3890) (by @roboz0r)
 * [JS/TS] Fix `uri.Host` to return the host name without the port (by @MangelMaxime)
+* [JS/TS] Fix TypeScript compilation by resolving type of `jsOptions` (#3894) (by @ManngelMaxime)
 
 ## 4.20.0 - 2024-09-04
 

src/Fable.Transforms/Replacements.fs

@@ -713,12 +713,17 @@ let makeGenericAverager (com: ICompiler) ctx t =
             "DivideByInt", divideFn
         ]
 
-let makePojoFromLambda com arg =
+let makePojoFromLambda com (arg: Expr) =
     let rec flattenSequential =
         function
         | Sequential statements -> List.collect flattenSequential statements
         | e -> [ e ]
 
+    let typ, genArgs =
+        match arg.Type with
+        | LambdaType(argType, _) -> argType, Some [ argType ]
+        | _ -> Any, None
+
     match arg with
     | Lambda(_, lambdaBody, _) ->
         (flattenSequential lambdaBody, Some [])
@@ -728,8 +733,8 @@ let makePojoFromLambda com arg =
             | _ -> None
         )
     | _ -> None
-    |> Option.map (fun members -> ObjectExpr(members, Any, None))
-    |> Option.defaultWith (fun () -> Helper.LibCall(com, "Util", "jsOptions", Any, [ arg ]))
+    |> Option.map (fun members -> ObjectExpr(members, typ, None))
+    |> Option.defaultWith (fun () -> Helper.LibCall(com, "Util", "jsOptions", typ, [ arg ], ?genArgs = genArgs))
 
 let makePojo (com: Compiler) caseRule keyValueList =
     let makeObjMember caseRule name values =

src/fable-library-ts/CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * [JS/TS] Fix escaping of `{` and `}` in FormattableString (#3890) (by @roboz0r)
 * [JS/TS] Fix `uri.Host` to return the host name without the port (by @MangelMaxime)
+* [JS/TS] Fix TypeScript compilation by resolving type of `jsOptions` (#3894) (by @ManngelMaxime)
 
 ## 1.4.3 - 2024-09-04
 

src/fable-library-ts/Util.ts

@@ -588,8 +588,8 @@ export function createObj(fields: Iterable<[string, any]>) {
   return obj;
 }
 
-export function jsOptions(mutator: (x: object) => void): object {
-  const opts = {};
+export function jsOptions<T>(mutator: (x: T) => void): T {
+  const opts = {} as T;
   mutator(opts);
   return opts;
 }

tests/Js/Main/JsInteropTests.fs

@@ -741,6 +741,16 @@ let tests =
         opts.foo |> equal "bar"
         opts.bar |> equal 5
 
+    testCase "jsOptions works when it is directly replaced as a POJO" <| fun () ->
+        let opts = jsOptions<JsOptions>(fun o ->
+            // This function call avoid the optimization to literal POJO
+            let foo () = "foo"
+            o.foo <- foo()
+            o.bar <- 5
+        )
+        opts.foo |> equal "foo"
+        opts.bar |> equal 5
+
     testCase "Stringifying a JS object works" <| fun () ->
         let fooOptional = importMember "./js/1foo.js"
         string fooOptional |> equal "much foo, much awesome"

tests/TypeScript/Fable.Tests.TypeScript.fsproj

@@ -46,6 +46,7 @@
     <Compile Include="../Js/Main/HashSetTests.fs" />
     <!-- <Compile Include="../Js/Main/ImportTests.fs" /> -->
     <!-- <Compile Include="../Js/Main/JsInteropTests.fs" /> -->
+     <Compile Include="LiteTsInteropTests.fs" />
     <Compile Include="../Js/Main/ListTests.fs" />
     <Compile Include="../Js/Main/MapTests.fs" />
     <Compile Include="../Js/Main/MiscTestsHelper.fs" />

tests/TypeScript/LiteTsInteropTests.fs

@@ -0,0 +1,37 @@
+module Fable.Tests.LiteTsInterop
+
+open System
+open Util.Testing
+open Fable.Core
+
+#if FABLE_COMPILER
+open Fable.Core.JsInterop
+open Fable.Core.DynamicExtensions
+open Fable.Core.Experimental
+#endif
+
+type JsOptions =
+    abstract foo: string with get, set
+    abstract bar: int with get, set
+let tests =
+  testList "LiteTsInterop" [
+    #if FABLE_COMPILER
+    testCase "jsOptions works" <| fun _ ->
+        let opts = jsOptions<JsOptions>(fun o ->
+            o.foo <- "bar"
+            o.bar <- 5
+        )
+        opts.foo |> equal "bar"
+        opts.bar |> equal 5
+
+    testCase "jsOptions works when it is directly replaced as a POJO" <| fun () ->
+        let opts = jsOptions<JsOptions>(fun o ->
+            // This function call avoid the optimization to literal POJO
+            let foo () = "foo"
+            o.foo <- foo()
+            o.bar <- 5
+        )
+        opts.foo |> equal "foo"
+        opts.bar |> equal 5
+    #endif
+  ]

tests/TypeScript/Main.fs

@@ -28,6 +28,7 @@ let allTests =
     HashSets.tests
     // Import.tests
     // JsInterop.tests
+    LiteTsInterop.tests
     Lists.tests
     Maps.tests
     Misc.tests